package com.android.inputmethod.norwegian;

import android.app.AlertDialog.Builder;
import android.content.Context;
import android.content.DialogInterface;
import android.preference.ListPreference;
import android.preference.Preference;
import android.util.AttributeSet;

/**
 * A {@link Preference} that displays a list of entries as
 * a dialog and allows multiple selections
 * <p>
 * This preference will store a string into the SharedPreferences. This string will be the values selected
 * from the {@link #setEntryValues(CharSequence[])} array.
 * </p>
 */
public class ListPreferenceMultiSelect extends ListPreference {
    //Need to make sure the SEPARATOR is unique and weird enough that it doesn't match one of the entries.
    //Not using any fancy symbols because this is interpreted as a regex for splitting strings.
    private static final String SEPARATOR = "OV=I=XseparatorX=I=VO";
    private static final String ALL_CHECKED = "#ALL#";
    
    private boolean[] mClickedDialogEntryIndices;

    public ListPreferenceMultiSelect(Context context, AttributeSet attrs) {
        super(context, attrs);
        
        mClickedDialogEntryIndices = new boolean[getEntries().length];
    }
 
    @Override
    public void setEntries(CharSequence[] entries) {
        super.setEntries(entries);
        mClickedDialogEntryIndices = new boolean[entries.length];
    }
    
    public ListPreferenceMultiSelect(Context context) {
        this(context, null);
    }

    @Override
    protected void onPrepareDialogBuilder(Builder builder) {
        CharSequence[] entries = getEntries();
        CharSequence[] entryValues = getEntryValues();
        
        if (entries == null || entryValues == null || entries.length != entryValues.length ) {
            throw new IllegalStateException(
                    "ListPreference requires an entries array and an entryValues array which are both the same length");
        }

        restoreCheckedEntries();
        builder.setMultiChoiceItems(entries, mClickedDialogEntryIndices, 
                new DialogInterface.OnMultiChoiceClickListener() {
                    public void onClick(DialogInterface dialog, int which, boolean val) {
                        mClickedDialogEntryIndices[which] = val;
                    }
        });
    }

    public static String[] parseStoredValue(CharSequence val) {
        if ( "".equals(val) )
            return null;
        else
            return ((String)val).split(SEPARATOR);
    }
    
    private void restoreCheckedEntries() {
        CharSequence[] entryValues = getEntryValues();
        
        String[] vals = parseStoredValue(getValue());
        if ( vals != null ) {
            for ( int j=0; j<vals.length; j++ ) {
                String val = vals[j].trim();
                for ( int i=0; i<entryValues.length; i++ ) {
                    CharSequence entry = entryValues[i];
                    if ( entry.equals(val) ) {
                        mClickedDialogEntryIndices[i] = true;
                        break;
                    }
                }
            }
        }
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
//        super.onDialogClosed(positiveResult);
        
        CharSequence[] entryValues = getEntryValues();
        if (positiveResult && entryValues != null) {
            StringBuffer value = new StringBuffer();
            for ( int i=0; i<entryValues.length; i++ ) {
                if ( mClickedDialogEntryIndices[i] ) {
                    value.append(entryValues[i]).append(SEPARATOR);
                }
            }
            
            if (callChangeListener(value)) {
                String val = value.toString();
                if ( val.length() > 0 )
                    val = val.substring(0, val.length()-SEPARATOR.length());
                setValue(val);
            }
        }
    }
    
    public boolean checkAllIfValueIsAll() {
        if(ALL_CHECKED.equals(getValue())) {
            for (int i = 0; i < mClickedDialogEntryIndices.length; i++)
                mClickedDialogEntryIndices[i] = true;
            onDialogClosed(true);
            return true;
        }
        return false;
    }
}